1. Field of the Invention
This invention relates generally to communication systems and, more particularly, to computer workstation conference systems that permit users to communicate via display screens and simultaneously point to areas of all the user screens.
2. Description of the Related Art
Communication systems that support group workstation conferences have been the subject of recent research and development. Such systems include, for example, multiple user terminals, comprising workstations or personal computers, connected together over a network. Each of the user terminals includes a display device that displays a conference window having a common work area. The conference support system permits multiple workstation users to join a conference in which the system keeps track of conference participants and provides the display device of each participant with the conference window. A workstation user who is a conference participant can place a variety of images, such as objects and messages, in the work area and the system will duplicate the images such that they are displayed in the work area of all the other conference participant display devices. Thus, the work area serves as a video "whiteboard" on which users can share information during a conference. Video images of the participants may or may not be transmitted among the workstations and displayed in the conference window. The workstations also may provide for audio transmission among the participants. In this way, conference participants can interactively exchange voice, video, and written information.
For easier and more precise communication, workstation conference participants should have a way of designating or pointing to objects displayed in the work area of the conference windows during the conference. A common means of providing such a capability is to provide conference participants with a display device pointer, such as a movable cursor or pointer icon that can be moved about the common work area. All of the conference participants should be able to point to objects or data in the common work area. Moreover, conference participants should be able to associate a pointer with its corresponding user. A variety of workstation conference support systems provide such capabilities.
A conference support system, for example, can provide a single pointer icon that is shared in turn among the conference participants. Each workstation user is provided with a pointer control device, such as a display mouse or track ball. Such a system requires a mechanism for obtaining and then exchanging control of the pointer icon. When one user is finished using the pointer, the user must relinquish control. Pointer control must then be acquired by another user, or re-acquired by the previous user. As each conference participant wishes to point to some part of the display work area, pointer control must be passed among the conference participants. This can be a slow and cumbersome process that inhibits effective communication during a conference.
A conference support system also can permit each conference participant to have a unique pointer icon, which the participant has control of at all times. All of the conference participants can have pointer icons simultaneously active and present in the common work area of the conference window. The multiple pointers moving about the work area only serve to increase clutter and confusion. It will be appreciated that communication during a conference can be quite confusing if there are many conference participants and they all try to use pointers simultaneously. In practice, communication can become confusing as soon as more than two users are working with pointers. The work area quickly becomes crowded with objects and pointer icons, and it becomes difficult to associate particular pointers with particular users.
From the discussion above, it should be apparent that there is a need for a computer communication and conference support system that permits each one of multiple workstation users to control pointers during a workstation conference while each pointer is clearly associated with its respective user. The present invention satisfies this need.